Grasil (Sildenafil)

Grasil is prescribed for conditions that benefit from increased nitric‑oxide mediated vasodilation, primarily involving the male reproductive system and pulmonary circulation.

• Treatment of erectile dysfunction in adult males.
• Management of pulmonary arterial hypertension to improve exercise capacity.
• Adjunct therapy for patients with secondary causes of erectile difficulty.
• Off‑label consideration for certain cases of Raynaud’s phenomenon under specialist guidance.
• Use in clinical trials evaluating sildenafil’s vascular effects.

The safety profile of Grasil reflects the typical adverse events associated with sildenafil, ranging from mild, transient symptoms to rare but serious complications.

Common

• Headache
• Flushing
• Indigestion or dyspepsia
• Nasal congestion
• Visual disturbances such as color tint changes
• Dizziness or light‑headed feeling
• Upset stomach or nausea
• Back pain or muscle aches
• Feeling of warmth in the face or chest

Serious

• Sudden loss of vision (non‑arteritic anterior ischemic optic neuropathy)
• Sudden loss of hearing
• Prolonged erection lasting more than four hours (priapism)
• Severe hypotension, especially when combined with nitrates
• Cardiac arrhythmias in patients with pre‑existing heart disease
• Allergic skin reactions such as rash or itching

Before initiating Grasil, healthcare providers assess several clinical factors to ensure safe use and to minimize the risk of adverse outcomes.

• Known hypersensitivity to sildenafil or any tablet excipients.
• Significant cardiovascular disease, such as recent myocardial infarction or unstable angina.
• Concurrent use of nitrates or nitric‑oxide donors.
• Severe liver impairment that may affect drug metabolism.
• Low blood pressure (systolic <90 mm Hg) or uncontrolled hypertension.
• History of priapism or anatomical penile abnormalities.
• Use in patients with retinitis pigmentosa is not recommended.
• Renal impairment requiring dialysis should be evaluated before prescribing.

Grasil can alter the activity of several other medicines; understanding these interactions helps avoid reduced efficacy or heightened toxicity.

Avoid

• Nitrates (e.g., nitroglycerin) because combined use may cause severe hypotension.
• Guanylate cyclase stimulators such as riociguat, which can lead to dangerous blood pressure drops.

Use with caution

• Alpha‑blockers (e.g., doxazosin) – monitor blood pressure closely.
• Antifungal agents like ketoconazole that increase sildenafil plasma levels.
• Certain antibiotics (e.g., erythromycin) that may elevate drug concentrations.
• Antiretroviral protease inhibitors (e.g., ritonavir) which can raise exposure.
• Cardiovascular drugs such as amlodipine that may potentiate hypotensive effects.
• Diuretics such as furosemide may enhance the blood‑pressure‑lowering effect.